1. Technical Field
The present inventive concept relates to a system timer and a mobile system including the same, and more particularly, to a system timer including a fractional (number) divider and a mobile system including the same.
2. Discussion of Related Art
Various methods are used to generate a clock signal required by an operating system (OS) in a mobile system. For example, in a method of generating a clock signal, which an OS requires, an oscillator is connected to the outside of a mobile system; however, this may increase the manufacturing cost of the mobile system and make it difficult to reduce the size of the mobile system. Another method utilizes an oscillator already existing inside the mobile system. For example, by using a divider, e.g., an integer divider, capable of dividing a clock signal output from the oscillator, a clock signal, which an OS requires, may be generated.
However, in the second method, when a period of a clock signal output from the integer divider is not a multiple of a cycle of a clock signal input to the integer divider, a clock signal that an OS requires may not be generated. In addition, when dividing a high-speed clock signal used in a mobile system, current consumed in a standby mode of the mobile system may be increased, thereby increasing current consumption of the entire mobile system.
Accordingly, there is a need for a device that generates its own clock signal to stably provide the clock signal to an OS.